scholarly journals Hyperspectral imaging for perioperative monitoring of microcirculatory tissue oxygenation and tissue water content in pancreatic surgery — an observational clinical pilot study

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Maximilian Dietrich ◽  
Sebastian Marx ◽  
Maik von der Forst ◽  
Thomas Bruckner ◽  
Felix C. F. Schmitt ◽  
...  
Keyword(s):  
Water Content ◽  
Hyperspectral Imaging ◽  
Sofa Score ◽  
Pancreatic Surgery ◽  
Tissue Oxygenation ◽  
Haemodynamic Monitoring ◽  
Tissue Water Content ◽  
Anaesthetic Induction ◽  
Tissue Water ◽  
Induction Of Anaesthesia

Abstract Background Hyperspectral imaging (HSI) could provide extended haemodynamic monitoring of perioperative tissue oxygenation and tissue water content to visualize effects of haemodynamic therapy and surgical trauma. The objective of this study was to assess the capacity of HSI to monitor skin microcirculation and possible relations to perioperative organ dysfunction in patients undergoing pancreatic surgery. Methods The hyperspectral imaging TIVITA® Tissue System was used to evaluate superficial tissue oxygenation (StO2), deeper layer tissue oxygenation (near-infrared perfusion index (NPI)), haemoglobin distribution (tissue haemoglobin index (THI)) and tissue water content (tissue water index (TWI)) in 25 patients undergoing pancreatic surgery. HSI parameters were measured before induction of anaesthesia (t1), after induction of anaesthesia (t2), postoperatively before anaesthesia emergence (t3), 6 h after emergence of anaesthesia (t4) and three times daily (08:00, 14:00, 20:00 ± 1 h) at the palm and the fingertips until the second postoperative day (t5–t10). Primary outcome was the correlation of HSI with perioperative organ dysfunction assessed with the perioperative change of SOFA score. Results Two hundred and fifty HSI measurements were performed in 25 patients. Anaesthetic induction led to a significant increase of tissue oxygenation parameters StO2 and NPI (t1–t2). StO2 and NPI decreased significantly from t2 until the end of surgery (t3). THI of the palm showed a strong correlation with haemoglobin levels preoperatively (t2:r = 0.83, p < 0.001) and 6 h postoperatively (t4: r = 0.71, p = 0.001) but not before anaesthesia emergence (t3: r = 0.35, p = 0.10). TWI of the palm and the fingertip rose significantly between pre- and postoperative measurements (t2–t3). Higher blood loss, syndecan level and duration of surgery were associated with a higher increase of TWI. The perioperative change of HSI parameters (∆t1–t3) did not correlate with the perioperative change of the SOFA score. Conclusion This is the first study using HSI skin measurements to visualize tissue oxygenation and tissue water content in patients undergoing pancreatic surgery. HSI was able to measure short-term changes of tissue oxygenation during anaesthetic induction and pre- to postoperatively. TWI indicated a perioperative increase of tissue water content. Perioperative use of HSI could be a useful extension of haemodynamic monitoring to assess the microcirculatory response during haemodynamic therapy and major surgery. Trial registration German Clinical Trial Register, DRKS00017313 on 5 June 2019

scholarly journals Algorithm for Mapping Kidney Tissue Water Content during Normothermic Machine Perfusion Using Hyperspectral Imaging

Algorithms ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 289
Author(s):  
Wenke Markgraf ◽  
Jannis Lilienthal ◽  
Philipp Feistel ◽  
Christine Thiele ◽  
Hagen Malberg
Keyword(s):  
Water Content ◽  
Hyperspectral Imaging ◽  
Wavelength Range ◽  
Kidney Tissue ◽  
Reflectance Spectra ◽  
Machine Perfusion ◽  
Least Squares Regression ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Normothermic Machine Perfusion

The preservation of kidneys using normothermic machine perfusion (NMP) prior to transplantation has the potential for predictive evaluation of organ quality. Investigations concerning the quantitative assessment of physiological tissue parameters and their dependence on organ function lack in this context. In this study, hyperspectral imaging (HSI) in the wavelength range of 500–995 nm was conducted for the determination of tissue water content (TWC) in kidneys. The quantitative relationship between spectral data and the reference TWC values was established by partial least squares regression (PLSR). Different preprocessing methods were applied to investigate their influence on predicting the TWC of kidneys. In the full wavelength range, the best models for absorbance and reflectance spectra provided Rp2 values of 0.968 and 0.963, as well as root-mean-square error of prediction (RMSEP) values of 2.016 and 2.155, respectively. Considering an optimal wavelength range (800–980 nm), the best model based on reflectance spectra (Rp2 value of 0.941, RMSEP value of 3.202). Finally, the visualization of TWC distribution in all pixels of kidneys’ HSI image was implemented. The results show the feasibility of HSI for a non-invasively and accurate TWC prediction in kidneys, which could be used in the future to assess the quality of kidneys during the preservation period.

scholarly journals Hyperspectral Imaging for the Evaluation of Microcirculatory Tissue Oxygenation and Perfusion Quality in Haemorrhagic Shock: A Porcine Study

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1829
Author(s):  
Maximilian Dietrich ◽  
Berkin Özdemir ◽  
Daniel Gruneberg ◽  
Clara Petersen ◽  
Alexander Studier-Fischer ◽  
...  
Keyword(s):  
Water Content ◽  
Hyperspectral Imaging ◽  
Fluid Therapy ◽  
Tissue Oxygenation ◽  
Haemorrhagic Shock ◽  
Control Group ◽  
High Dose ◽  
Tissue Water ◽  
Norepinephrine Infusion ◽  
Tissue System

Background: The ultimate goal of haemodynamic therapy is to improve microcirculatory tissue and organ perfusion. Hyperspectral imaging (HSI) has the potential to enable noninvasive microcirculatory monitoring at bedside. Methods: HSI (Tivita® Tissue System) measurements of tissue oxygenation, haemoglobin, and water content in the skin (ear) and kidney were evaluated in a double-hit porcine model of major abdominal surgery and haemorrhagic shock. Animals of the control group (n = 7) did not receive any resuscitation regime. The interventional groups were treated exclusively with either crystalloid (n = 8) or continuous norepinephrine infusion (n = 7). Results: Haemorrhagic shock led to a drop in tissue oxygenation parameters in all groups. These correlated with established indirect markers of tissue oxygenation. Fluid therapy restored tissue oxygenation parameters. Skin and kidney measurements correlated well. High dose norepinephrine therapy deteriorated tissue oxygenation. Tissue water content increased both in the skin and the kidney in response to fluid therapy. Conclusions: HSI detected dynamic changes in tissue oxygenation and perfusion quality during shock and was able to indicate resuscitation effectivity. The observed correlation between HSI skin and kidney measurements may offer an estimation of organ oxygenation impairment from skin monitoring. HSI microcirculatory monitoring could open up new opportunities for the guidance of haemodynamic management.

scholarly journals Isoflurane in Contrast to Propofol Promotes Fluid Extravasation during Cardiopulmonary Bypass in Pigs

2013 ◽  
Vol 119 (4) ◽  
pp. 861-870 ◽  
Author(s):  
Hege Kristin Brekke ◽  
Stig Morten Hammersborg ◽  
Steinar Lundemoen ◽  
Arve Mongstad ◽  
Venny Lise Kvalheim ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Water Content ◽  
Interstitial Fluid ◽  
Outcome Analysis ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Edema Formation ◽  
Fluid Extravasation ◽  
Isoflurane Anesthesia ◽  
Total Tissue

Abstract Background: A highly positive intraoperative fluid balance should be prevented as it negatively impacts patient outcome. Analysis of volume-kinetics has identified an increase in interstitial fluid volume after crystalloid fluid loading during isoflurane anesthesia. Isoflurane has also been associated with postoperative hypoxemia and may be associated with an increase in alveolar epithelial permeability, edema formation, and hindered oxygen exchange. In this article, the authors compare fluid extravasation rates before and during cardiopulmonary bypass (CPB) with isoflurane- versus propofol-based anesthesia. Methods: Fourteen pigs underwent 2 h of tepid CPB with propofol (P-group; n = 7) or isoflurane anesthesia (I-group; n = 7). Fluid requirements, plasma volume, colloid osmotic pressures in plasma and interstitial fluid, hematocrit levels, and total tissue water content were recorded, and fluid extravasation rates calculated. Results: Fluid extravasation rates increased in the I-group from the pre-CPB level of 0.27 (0.13) to 0.92 (0.36) ml·kg−1·min−1, but remained essentially unchanged in the P-group with significant between-group differences during CPB (pb = 0.002). The results are supported by corresponding changes in interstitial colloid osmotic pressure and total tissue water content. Conclusions: During CPB, isoflurane, in contrast to propofol, significantly contributes to a general increase in fluid shifts from the intravascular to the interstitial space with edema formation and a possible negative impact on postoperative organ function.

Detection of bark lesions caused by Phytophthoracinnamomi in Eucalyptusmarginata with the plant impedance ratio meter and the Shigometer

1987 ◽  
Vol 17 (10) ◽  
pp. 1228-1233 ◽  
Author(s):  
Joanna T. Tippett ◽  
Joanne L. Barclay
Keyword(s):  
Water Content ◽  
Electrical Resistance ◽  
Water Status ◽  
Healthy Tissue ◽  
Plant Tissues ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Impedance Ratio ◽  
New Instrument ◽  
Electrical Admittance

A new instrument, the plant impedance ratio meter (PIRM), has been used to determine the extent of lesions caused by Phytophthoracinnamomi Rands in Eucalyptusmarginata Sm. The performance of the PIRM, which measures electrical admittance (the inverse of impedance) of plant tissues at two frequencies (from which an impedance ratio is calculated), was evaluated and compared with that of the Shigometer. The electrical admittance measured at 1 and 10 kHz (PIRM) and the electrical resistance (Shigometer) of healthy tissue varied with both the depth of tissue probed and the water status of stems. However, the impedance ratios (calculated from the admittance values) remained relatively constant for healthy tissue and changes were independent of depth of probing. Hence, changes in ratios indicated a change in tissue condition or necrosis rather than changes in either tissue water content or depth of probing. The impedance ratios recorded for healthy bark tissues were consistently higher than those for the P. cinnamomi lesions in E. marginata. Trends in electrical resistance measured across the boundaries of the lesions with the Shigometer were variable depending on lesion age. The PIRM was used successfully to detect P. cinnamomi lesions in E. marinate and lesion fronts were predicted to an accuracy of ± 7.2 mm (n = 150), lesions being up to 1.0 m long at the time stems were harvested.

scholarly journals Bedside hyperspectral imaging for the evaluation of microcirculatory alterations in perioperative intensive care medicine: a study protocol for an observational clinical pilot study (HySpI-ICU)

BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e035742 ◽  
Author(s):  
Maximilian Dietrich ◽  
Sebastian Marx ◽  
Thomas Bruckner ◽  
Felix Nickel ◽  
Beat Peter Müller-Stich ◽  
...  
Keyword(s):  
Hyperspectral Imaging ◽  
Organ Dysfunction ◽  
Pancreatic Surgery ◽  
Near Infrared ◽  
Haemodynamic Monitoring ◽  
Healthy Controls ◽  
Study Results ◽  
Infrared Spectral ◽  
Registration Number ◽  
Tissue System

IntroductionNormalisation of macrocirculatory parameters during resuscitation therapy does not guarantee the restoration of microcirculatory perfusion in critical illness due to haemodynamic incoherence. Persistent microcirculatory abnormalities are associated with severity of organ dysfunction and mandate the development of bedside microcirculatory monitoring. A novel hyperspectral imaging (HSI) system can visualise changes in skin perfusion, oxygenation and water content at the bedside. We aim to evaluate the effectiveness of HSI for bedside monitoring of skin microcirculation and the association of HSI parameters with organ dysfunction in patients with sepsis and major abdominal surgery.Methods and analysisThree independent groups will be assessed and separately analysed within a clinical prospective observational study: (1) 25 patients with sepsis or septic shock (according to sepsis-3 criteria), (2) 25 patients undergoing pancreatic surgery and (3) 25 healthy controls. Patients with sepsis and patients undergoing pancreatic surgery will receive standard therapy according to local protocols derived from international guidelines. In addition, cardiac output of perioperative patients and patients with sepsis will be measured. Healthy controls undergo one standardised evaluation. The TIVITA Tissue System is a novel HSI system that uses the visible and near-infrared spectral light region to determine tissue microcirculatory parameters. HSI analysis (hand/knee) will be done in parallel to haemodynamic monitoring within defined intervals during a 72-hour observation period. HSI data will be correlated with the Sequential Organ Failure Assessment score, global haemodynamics, inflammation and glycocalyx markers, surgical complications and 30-day outcome.Ethics and disseminationThe protocol has been approved by the local ethics committee of the University of Heidelberg (S-148/2019). Study results will be submitted to peer-reviewed journals and medical conferences.Trial registration numberDRKS00017313; Pre-results.

USE OF CONTROLLED ENVIRONMENTS FOR WINTER CEREAL COLD HARDINESS EVALUATION: CONTROLLED FREEZE TESTS AND TISSUE WATER CONTENT AS PREDICTION TESTS

1989 ◽  
Vol 69 (2) ◽  
pp. 355-366 ◽  
Author(s):  
A. L. BRULE-BABEL ◽  
D. B. FOWLER
Keyword(s):  
Water Content ◽  
Cold Acclimation ◽  
Cold Hardiness ◽  
Screening Method ◽  
Strong Relationship ◽  
Winter Rye ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Winter Cereal ◽  
Controlled Environments

Field survival is the most commonly employed method of evaluating the winter hardiness of cereals. However, the inherent difficulties with field trials have stimulated a continued interest in the use of controlled environments and prediction tests for the evaluation of cold hardiness. In the present studies, cold hardiness expression of wheat (Triticum aestivum L.) cultivars acclimated in controlled environments was found to be similar to that reported for field conditions in Saskatchewan, Canada. LT50 and tissue water content measurements on wheat and rye (Secale cereale L.) cultivars acclimated in controlled environments were highly correlated with cultivar field survival ability. Investigation of the relationship between field survival and tissue water content during cold acclimation in controlled environments indicated that, to be effective as a screening method for cold hardiness, measurements of tissue water content should be made on fully acclimated plants for which the acclimation conditions have been rigorously controlled. Level of acclimation was not as critical for cold hardiness screening when LT50 measurements were utilized; however, maximum resolution also required fully acclimated plants. Although a strong relationship (r = −0.80 to −0.89) was found to exist with field survival potential, an inability to detect small, but important, differences without excessive replication would generally restrict the use of LT50 and tissue water content to situations where large homogeneous plant populations were available and only coarse screens for cold hardiness were required.Key words: Cold acclimation, winter wheat, winter rye, cold hardiness, water content, replication

Responses of the moss Tortula ruralis to desiccation treatments. II. Variations in desiccation tolerance

1981 ◽  
Vol 59 (12) ◽  
pp. 2707-2712 ◽  
Author(s):  
Mark W. Schonbeck ◽  
J. Derek Bewley
Keyword(s):  
Water Content ◽  
Desiccation Tolerance ◽  
Dry Weight ◽  
Severe Damage ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Tortula Ruralis

Variations in the apparent desiccation tolerance of the moss Tortula ruralis were traced to several causes. When the moss was kept continuously hydrated for several days, desiccation tolerance tended to decrease ("dehardening"). Conversely, daily episodes of drying and rehydration induced hardening so that the moss could tolerate rapid drying to a tissue water content of 0.008 g∙g dry weight−1.Different clumps of moss showed very different degrees of desiccation tolerance. The least tolerant samples suffered severe damage after rapid drying, whereas the most tolerant suffered little damage, and did not deharden during 3 days continuous hydration.

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